The coelacanth is a rare deep-sea fish that was thought to have gone extinct around 66 million years ago, until a living specimen was discovered off the coast of South Africa in 1938. This ancient fish belongs to the order Actinistia and is known for its distinctive lobed pectoral and pelvic fins, which resemble the limbs of land vertebrates. Coelacanths can grow up to 2 meters (6.5 feet) in length and have a unique, thick, and bony structure. They are primarily found in deep waters, typically at depths of 150 to 700 meters (490 to 2,300 feet). Their diet consists mainly of cephalopods and other fish, making them important predators in their marine ecosystem.